US4228826A - Interlocking, laminated refractory for covering a pipe - Google Patents

Interlocking, laminated refractory for covering a pipe Download PDF

Info

Publication number
US4228826A
US4228826A US05/950,633 US95063378A US4228826A US 4228826 A US4228826 A US 4228826A US 95063378 A US95063378 A US 95063378A US 4228826 A US4228826 A US 4228826A
Authority
US
United States
Prior art keywords
refractory
slurry
ceramic fiber
segment
main
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US05/950,633
Other languages
English (en)
Inventor
Frank Campbell, Jr.
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Cooper Industries LLC
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to US05/950,633 priority Critical patent/US4228826A/en
Priority to CA330,374A priority patent/CA1132450A/en
Priority to MX17834379A priority patent/MX152389A/es
Priority to JP8638279A priority patent/JPS5554793A/ja
Priority to ES483459A priority patent/ES483459A1/es
Priority to DE7979302116T priority patent/DE2966759D1/de
Priority to AT79302116T priority patent/ATE6495T1/de
Priority to EP19790302116 priority patent/EP0010385B1/en
Priority to DD21611879A priority patent/DD146487A5/de
Priority to PL21893179A priority patent/PL218931A1/xx
Priority to US06/173,211 priority patent/US4304267A/en
Application granted granted Critical
Publication of US4228826A publication Critical patent/US4228826A/en
Assigned to CAMERON IRON WORKS, INC. reassignment CAMERON IRON WORKS, INC. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: CAMPBELL, FRANK, JR.
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L59/00—Thermal insulation in general
    • F16L59/02—Shape or form of insulating materials, with or without coverings integral with the insulating materials
    • F16L59/021—Shape or form of insulating materials, with or without coverings integral with the insulating materials comprising a single piece or sleeve, e.g. split sleeve, two half sleeves
    • F16L59/024—Shape or form of insulating materials, with or without coverings integral with the insulating materials comprising a single piece or sleeve, e.g. split sleeve, two half sleeves composed of two half sleeves
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B30/00—Compositions for artificial stone, not containing binders
    • C04B30/02—Compositions for artificial stone, not containing binders containing fibrous materials
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B37/00—Component parts or details of steam boilers
    • F22B37/02—Component parts or details of steam boilers applicable to more than one kind or type of steam boiler
    • F22B37/10—Water tubes; Accessories therefor
    • F22B37/107—Protection of water tubes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D1/00—Casings; Linings; Walls; Roofs
    • F27D1/0043—Floors, hearths
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S428/00—Stock material or miscellaneous articles
    • Y10S428/902—High modulus filament or fiber

Definitions

  • a typical furnace In furnaces used throughout the metallurgical and related industries to heat a slab, billet, bloom or other raw steel shape, a typical furnace includes a complex network of vertical and horizontal water-cooled pipes which support an additional network of horizontal water-cooled skid rails along which slabs, billets, blooms, or other raw steel shapes are pushed or walked through the furnace.
  • the metallurgical furnace is an open system; that is, heat which is transferred to the metal pipe network is conducted by the flowing water in the pipes to a point outside the furnace and is not recoverable. Accordingly, vast amounts of heat losses occur and correspondingly unnecessary amounts of energy are expended to replace the heat loss as a result of the heat transfer into the water-cooled pipe network.
  • refractory materials have been utilized in order to reduce the amount of heat loss from the furnace through the water-cooled pipe infrastructure.
  • the use of pre-fired or chemically bonded refractory materials which are welded, studded, wired, clipped or anchored with interlocking anchor straps is well known.
  • refractory concretes have even been formed in place around the pipe surfaces which are supported by any number and type of metallic anchors welded to the pipe surface. Almost without exception these forms of insulation have failed within a relatively short period of operation because of the inherent friability and susceptibility to fracture of the heavy, brittle fired ceramic refractory materials.
  • ordinary high temperature ceramic fibers and ceramic fiber blankets as insulators around the water-cooled pipe has proven unsatisfactory for a number of reasons: first, the ordinary high temperature ceramic fiber blanket is susceptible to chemical reaction with scale and slag which is produced during the furnace operation; second, ordinary ceramic fiber blankets are inherently susceptible to erosion by the velocities of the gases within the furnace; and third, the ceramic fiber blankets have been difficult to attach to the pipe and suffer a notable shrinkage due to the high temperatures of the furnace.
  • the device in the '160 patent relates to a dense, preburned ceramic refractory formed in interlocking shapes which are positioned by a number of studs 35 welded to the pipe which are received by the arcuate recesses 17 and the refractory shape.
  • a ceramic blanket is positioned between the water pipe and the preburned ceramic tile.
  • the device in the '160 patent weighs approximately 35 to 40 pounds per lineal foot and is rather rigid. Hence, vibrations in the furnace are transmitted to the preburned ceramic tile and frequently induce fracture along the interlocking portions. The massive weight of the preburned ceramic tile also induces the fracture of the studs which support the refractory.
  • the great weight of the refractory on the ceramic blanket underneath in combination with furnace vibrations compresses the blanket, chafes holes within the blanket and generally reduces the thermal barrier characteristics of the blanket.
  • the inventor of the '160 device who is also the applicant herein, has discovered that because of the weight of the preburned ceramic tile, the length of the refractory is limited to relatively short elements as is the length of its interlocking portion. Thus, the interlocking characteristics of the segments is less than desirable and sufficient seams occur along the fitted pieces which allow high velocity, high temperature gases and slag to pass through and to attack and destroy the blanket underneath.
  • the device in the '661 patent involves an interlocking outer refractory layer unsupported by studs welded to the pipe.
  • the amount of time and effort expended in interlocking the numerous outer pieces is significant as is the number of seams defined by the individual pieces.
  • the '636 device again uses a preburned ceramic tile material having an inner layer of semi-cylindrical tiles held together on the pipe by a "C"-shaped ceramic refractory collar which is slid over the split tiles as they are held together. Again, the effort and time expended in insulating the pipe is less than satisfactory.
  • the rigidity and weight of the device is less than desirable in terms of transmission of vibrations, and flexion of the pipe to the refractory which causes fracture of the refractory and deformation and wear of the insulating blanket underneath the tiles.
  • the present invention relates to an interlocking laminated refractory covering for a water-cooled pipe and a method for manufacturing same.
  • the refractory covering in its commercial form includes two main segments.
  • Each main segment further includes a partial cylindrical wall which is termed a body segment for purposes of this application, and a pair of protuberances which are angularly spaced apart from the body segment by a corresponding pair of recesses.
  • the body segment, protuberances and corresponding recesses of each main segment all lie in the same cylindrical surface of revolution so that the two main segments can be fitted together around a pipe to form an interlocking, cylindrical refractory shape which effectively insulates the water-cooled pipe inside the furnace.
  • a series of interlocking main segments are fitted together in order to insulate an entire pipe.
  • the refractory shape is made from light-weight ceramic fibers which are highly resistant to heat flow.
  • the ceramic fiber refractory is much lighter in weight and is less brittle than the conventional preburned ceramic tiles and allows each pair of interlocking main segments to be longer longitudinally and to have a greater interlock surface area than previous interlocking cylindrical shapes made of preburned ceramic tiles. Hence, a more intimate fit is obtained which reduces the deleterious effects of high temperature convection and slag migration through the seams of the refractory which quickly destroy the effectiveness of a ceramic blanket located between the water-cooled pipe and the refractory shape.
  • the present invention includes a laminated ceramic fiber construction having an inner ceramic fiber layer, an outer ceramic fiber layer and a metal or ceramic fibric mesh reinforcement disposed between the inner and outer ceramic fiber layers.
  • the inner ceramic fiber layer is less resistant to attack by furnace gases and corrosive slags and is less expensive to manufacture than the outer ceramic fiber layer which must withstand significantly higher temperatures and exposure to corrosive furnace slags and furnace gases.
  • the outer ceramic fiber layer when subjected to furnace temperatures in the 2600° F. range, generally permits the wire mesh reinforcement to function in a temperature range which will insure sufficient strength of the metal mesh which in turn assists the supporting of the entire refractory shape.
  • the inner ceramic fiber layer further reduces heat flow from the furnace to the water-cooled pipe.
  • the use of a light-weight, laminated ceramic fiber refractory reduces the crushing forces on the inner ceramic fiber blanket which historically have resulted from the massive weight of the preburned ceramic tiles.
  • the reduction of the crushing forces, which forces compact and chafe the inner ceramic fiber blanket extends both the useful life and the thermal effectiveness of the fiber blanket.
  • the coefficient of thermal conductivity of ceramic fiber is significantly lower than the prefired ceramic tiles presently in use.
  • the resulting insulator is significantly more effective than present refractories in use with metallurgical furnaces.
  • the manufacture of the laminated refractory shape utilizes a perforated mold whose perforations are in communication with a vacuum source.
  • a slurry from which the inner layer is formed can be maintained at room temperature.
  • the inner layer slurry includes a mixture of conventional basic fiber bulk material, a binder including a colloidal silica or colloidal alumina, a starch and a quantity of water.
  • the perforated vacuum mold is inserted into the slurry for the inner layer, the colloidal silica, a relatively small portion of starch bond system and a majority of the water are drawn through the perforations while the ceramic fibers tend to form a bonded mat around the perforated mold.
  • the outer ceramic fiber slurry mixture may consist of the same or similar thermal resistant ceramic fibers but in a ratio which utilizes a greater amount of higher temperature, slag, and furnace gas resistant fibers than the slurry used in the manufacture of the inner layer.
  • the entire combination is removed from the second slurry, the perforated mold is removed from the refractory shape, the refractory shape is preferably placed upon a mandrel to maintain the shape of the refractory as it is cured in an oven and any necessary machining and cutting is performed in order to produce a substantially cylindrical shape.
  • the cylindrical shape can then be cut to produce two main segments which are interlocking.
  • the energy required to cure the vacuum-formed, ceramic fiber refractory is significantly less than the energy requirement to cure conventional preburned ceramic tile shapes.
  • the resulting new refractory shape eliminates the need for the welding of metal studs to the pipe in order to anchor the refractory and the need to cement or band conventional semi-circular insulators presently used on water-cooled pipes. Hence, the labor expended on the installation of the refractory as described and claimed herein is remarkably reduced.
  • Another form of manufacture of the present invention replaces the laminated structure with a continuous spectrum of vacuum-formed, ceramic fiber material having varying characteristics of thermal conductivity which produce a substantially similar ceramic fiber refractory as the laminated construction.
  • Such a construction can be obtained by rotating a cylindrical mold at high speeds so that the more dense, thermally resistant fiber materials migrate toward the outer portions of the refractory shape while the lighter, less thermally conductive fibers remain at the inner portions of the shape.
  • a mold can be rotated while a more expensive, low thermally conductive material is applied to the mold as the content of the material being applied is altered to include an increasing amount of a less expensive, more thermally conductive ceramic fiber material.
  • Still another object of the present invention is to provide a refractory shape of low thermal conductivity which substantially reduces the energy expended in the manufacture of the refractory as well as the energy lost through the water-cooled pipes comprising the pipe network in the metallurgical furnace.
  • Another object of the present invention is to provide interlocking ceramic fiber refractory shape which reduces the necessary labor expenditure to mount the refractory shape.
  • a further object of the present invention is to provide a ceramic fiber refractory easily formed by means of a perforated vacuum mold.
  • Yet another object of the present invention is to provide a low-density, interlocking, vacuum-formed composite ceramic fiber refractory in which the stresses in the interlock area are significantly reduced thereby reducing the failure in the interlock area due to fracture and fatigue.
  • An even further object of the present invention is to provide a low-density, ceramic fiber refractory in which the crushing forces of the refractory upon a fiber blanket positioned between the pipe and the refractory are substantially reduced.
  • Another object of the present invention is to provide a low-density, vacuum-formed ceramic fiber refractory which is positioned around a water pipe without the use of anchoring devices such as metal studs welded to the pipe.
  • FIG. 1 is a perspective view of a typical water-cooled pipe network utilized in a metallurgical furnace.
  • FIG. 2 is a perspective view of the present invention showing a water-cooled pipe, a ceramic fiber blanket therearound, and the surrounding interlocking engagement of the main segments of the refractory shape.
  • FIG. 3 shows an exploded view in perspective of the interlocking main segments of the refractory further showing the interlocking characteristics and method of interlocking the main segments.
  • FIG. 4 is a side view of the present invention generally showing the seams defined by the protuberances, recesses, body segments and voids of two interlocked main segments.
  • FIG. 5 is a cross-section along lines 4--4 generally showing the radial relationship among the pipe, ceramic fiber blanket, inner ceramic fiber layer, metal mesh and outer ceramic fiber layer.
  • FIG. 6 is a side view of another embodiment of the present invention showing the seams defined by the tapered protuberances, the conformingly tapered recesses, the tapered body segments and the voids of the two interlocked main segments.
  • FIG. 7 is an exploded view in perspective showing another embodiment of the present invention in which two parallel pipes are insulated with a substantially elliptical refractory.
  • FIG. 1 diagrammatically shows a pusher type metallurgical furnace having a series of parallel skid rails 50 each having a metal strip 52 which supports the slab shape as the shape is propelled across the skid rail system.
  • Horizontal support pipes 54 and vertical support pipes 56 as well as the water-cooled skid rail 50 all conduct flowing water.
  • the heat which is transferred from the interior of the furnace into the metal strip 52 is then conducted by the water flowing in the water-cooled portion of the skid rail 50 and the horizontal pipes 54 and vertical pipes 56, which form the infrastructure support system for the skid rails, to a point outside the furnace system.
  • FIG. 1 diagrammatically shows a pusher type metallurgical furnace having a series of parallel skid rails 50 each having a metal strip 52 which supports the slab shape as the shape is propelled across the skid rail system.
  • Horizontal support pipes 54 and vertical support pipes 56 as well as the water-cooled skid rail 50 all conduct flowing water.
  • the heat which is transferred from the interior of the furnace into the metal strip 52 is then conducted
  • FIG. 2 shows a partially exploded view of a water-cooled pipe having two full units of the refractory 2 and a main segment 13 in position around the pipe 20 having a cylindrical passageway 23 therethrough suitable for transporting a fluid therein.
  • Located around the exterior surface 24 of the water-cooled pipe 20 is a layer of a conventional high-temperature pliable ceramic fiber blanket 26 which is known today in the industry.
  • the ceramic fiber blanket is preferably one-quarter inch to one inch thick and is taped temporarily around the pipe until such time as the refractory 2 is applied therearound.
  • Each main segment 13 of the refractory 2 includes an inner ceramic fiber layer 32, an outer ceramic fiber layer 30 and a metal mesh reinforcement 34 disposed therebetween.
  • the outer ceramic fiber layer 30 and the inner ceramic fiber layer 32 can be of an identical material.
  • the inner layer 32 of the present invention can be less resistant to furnace temperatures and attack by slag and furnace gases than the outer layer 30.
  • the refractory 2 can be manufactured at reduced cost.
  • Each ceramic fiber layer contains proportions of a 2300° F. ceramic fiber bulk, a 2600° F. ceramic bulk and/or a 3000° F. ceramic fiber bulk. The precise ratios of one fiber bulk to another is a result of the furnace temperatures encountered, the allowable or desired thickness of the refractory and the permitted cost of manufacture.
  • the inner layer can be formed from a slurry having the following relative weights:
  • a preferable colloidal silica is manufactured by E. I. du Pont de Nemours & Co. under the trademark "LUDOX HS-40.”
  • a suitable starch for the slurry is described in U.S. Pat. No. 3,224,927.
  • a colloidal alumina may be substituted for the colloidal silica in the appropriate molecular weight.
  • the purpose of the starch is to maintain the silica binder in a colloidal state, during the forming operation.
  • the starch which is organic is burned out during the subsequent curing operation leaving a substantially inorganic bond.
  • a suitable slurry for the formation of the outer ceramic fiber layer 30 is, by way of example and not by limitation, formed according to the following:
  • the metal mesh reinforcement 34 which is disposed between the inner layer 32 and the outer 30 of the refractory 2 can be any material which substantially maintains its rigidity and reinforcement characteristics in continuous operating temperatures which occur at a predetermined point of depth in the thickness of the refractory.
  • the inside furnace temperature is approximately 2400°-2500° F. and the metal mesh reinforcement is disposed at a depth in the refractory 2 wherein the metal mesh 34 operates at a continuous temperature of approximately 1500° F. to 2000° F.
  • the metal mesh experiences a continuous operating temperature in the neighborhood of 1500° F.
  • the metal mesh can be a woven wire, having a construction similar to that found in a screen door, or an expanded metal mesh which is well known in the industry today.
  • the metal mesh is preferably made from a group of chromium-nickel steels having standard American Iron & Steel Institute (AISI) numbers of 304, 309, 316, 310 and RA330.
  • AISI American Iron & Steel Institute
  • RA330 is the preferred alloy if cost is of little consideration.
  • the 310 alloy is slightly less acceptable but more economical to use and retains a 3500 psi tensile strength at 2400° F. and has a continuous operating temperature of 2100° F.
  • the metal mesh can assume many shapes and dimensions, the most suitable metal mesh has two to eight openings per inch and a strand size or thickness of 0.025 through 0.100 inches.
  • Another suitable mesh is a woven ceramic fiber mesh which is a woven braided or knitted fabric manufactured by the Three M Company from a yarn called 3M Brand Ceramic Fiber.
  • the mesh has a use temperature limit of approximately 2300° F.
  • the refractory shape 2 includes two substantially identical main segments 13. Each main segment has a partial cylindrical body segment 6 having radially aligned edge surfaces 7 and 11.
  • the body segment 6 is partially defined by a pair of longitudinally extending surfaces 8 and 9 which extend radially through the inner layer 32, outer layer 30 and metal mesh 34 and longitudinally less than the main segment 13.
  • a pair of protuberances 10 and 15 are partially defined by the surfaces 12, 27 respectively, which are normal to the longitudinal axis of the main segment 13, and the radially aligned and longitudinally extending surfaces 17, 14 and 21, 59 respectively.
  • the protuberances 10 and 15 are angularly spaced apart from the main body 6 by the recesses 16 and 29 which are generally defined by the surfaces 17 and 21, a portion of the surfaces 8 and 9, and the surface 19 and its counterpart (not shown), respectively, which are normally aligned to the longitudinal axis of the main segment 13.
  • the body segment 6, the recesses 16 and 29, and the protuberances 10 and 15 lie within a common cylindrical surface of rotation.
  • the protuberances 10 and 15 are further spaced apart from one another by a void 28.
  • the protuberances 10 and 15, and the body segment 6 of each main segment can have tapered surfaces 17, 14 and 21, 59, and 8, 9, respectively.
  • the tapering of the surfaces of the protuberances and the body segments offers the additional feature of insuring a more intimate fit between the protuberances 10 and 15 as they are received within the recesses 16 and 29.
  • the more intimate fit can be obtained by overinserting the two main segments 13 into an interlocking relationship and then cutting the end surfaces of the refractory 2 so that the end surfaces 7 of each main segment 13 are substantially aligned with the conforming surfaces 11 when the main segments 13 are interlocked.
  • each main segment 13 conform closely to the corresponding recesses 16 and 29.
  • the body segment 6 of each main segment 13 closely conforms to the void 28. Accordingly, when each main segment 13 is rotated around a longitudinal axis 180° from one another and further rotated 180° around a vertical axis and are aligned along a common longitudinal axis, the body segment 6 of one segment is closely received by the void 28 of the other segment, and the protuberances 10 and 15 are likewise closely received by the recesses 16 and 29 of the other main segment such that a substantially cylindrical, interlocking refractory 2 results.
  • the seams which are defined by the interlocking portions of the refractory 2 are substantially closed and resistant to the entry of slag and high-velocity convection which occurs within a metallurgical furnace.
  • the water-cooled pipe is first wrapped with a one-quarter inch through one inch thick layer of a high-temperature, pliable ceramic fiber blanket 26 which is taped around the pipe 20.
  • a first main segment 13 of the refractory 2 is positioned upon the surface of the water-cooled pipe 20 wrapped with the ceramic fiber blanket 26.
  • the other main segment 13 of the interlocking refractory 2 is properly oriented to facilitate the longitudinal engagement of the interlocking protuberances 10 and 15 with the recesses 16 and 29.
  • the two interlocking main segments 13 are then urged radially inwardly in order to compress the pliable ceramic fiber blanket and then pushed longitudinally toward one another in order to effectuate the interlock and to minimize the seams between the two interlocking main segments 13. Repetition of the above-noted procedure is continued until the desired length of refractory covers the water-cooled pipe 20. As junctions between horizontal and vertical pipes are reached, reduced lengths of the refractory 2 can be used in order to minimize the remaining exposed segments of the water pipe 20. Any conventional wrapping or suitable refractory cement can be used in the immediate area of the intersections.
  • a suitable high-temperature slurry coating material such as air or heat-setting mortar
  • one such surface coating is manufactured by Babcock & Wilcox Company according to the approximate chemical analysis:
  • the resulting compound is a self-curing high temperature protective coating providing an additional degree of surface hardness, resistance to slag penetration, and resistance to erosion of the ceramic fiber.
  • Another coating which is self curing contains 95% ZrO 2 which can also be applied cold.
  • a first slurry containing, for example, the ceramic fibers the colloidal silica, organic cationic starch and water is formed in accordance with the amounts noted heretofor.
  • the slurry is agitated or stirred in order to assist in the maintenance of the colloidal state within the slurry.
  • a perforated cylindrical male mold (not shown) whose perforations are in communication with a partial vacuum source, is inserted into the slurry.
  • the colloidal silica medium, the starch and the water within the slurry are drawn through the perforations by the vacuum effect.
  • the ceramic fibers are significantly long and generally do not pass through the perforations of the mold.
  • the ceramic fibers tend to form a mat around the perforated vacuum mold.
  • the mat around the perforated vacuum mold is more dense when nearest the mold and is less dense as it is formed radially outwardly and away from the mold.
  • the density, and to some degree the rigidity, of the mat can be varied.
  • the bark surface can be, but is not necessarily required to be, smooth before superimposing the metal mesh 34 therearound.
  • the mesh can be prepositioned in the mold prior to the forming of the first layer, the first layer formed to a point where it is built up to the mesh and then placed in the second slurry for forming of the final layer.
  • the combination of the perforated vacuum mold, inner layer 32 and superimposed metal mesh 34 is then inserted into a second slurry such as, for example, a second slurry described hereinabove. Because the inner layer 32 is sufficiently porous, the vacuum-like effect communicates through the perforations in the vacuum mold, through the metal mesh and into the second slurry. Hence, a ceramic fiber mat is developed around the metal mesh 34 until such time as the desired thickness occurs.
  • the perforated vacuum mold is then withdrawn from the second slurry leaving an outer ceramic fiber layer 30 deposited around the metal mesh 34.
  • the perforated vacuum mold is then removed from the combination of the inner ceramic fiber layer 32, the metal mesh 34 and the outer ceramic fiber layer 30 which substantially comprises the refractory shape 2.
  • the refractory 2 is then positioned on a suitable mandrel shape (not shown) and cured.
  • the refractory 2 is cured in a temperature range of approximately 180° F. through 500° F. for a period of four through eight hours. Forced convection in the curing oven will minimize the curing time.
  • the new combination of a laminated ceramic fiber refractory not only saves energy by reducing the heat loss within a metallurgical furnace, but also substantially reduces the energy requirement to cure the refractory itself.
  • dense prefired ceramic refractories have generally required curing at a temperature of 2700° F. Approximately sixteen hours are required to fire a furnace to 2700° F.
  • the conventional preburned ceramic refractories have then been cured at 2700° F. for six to eight hours.
  • the furnace has then slowly been cooled from 2700° F. to ambient temperature and the fired refractories have then been removed from the furnace.
  • the total time involved has been thirty to forty hours and the energy required to produce the requisite temperatures has been immense.
  • the manufacture of the new interlocking, laminated vacuum-formed ceramic fiber refractory requires an average of only six hours in a continuous oven process at a temperature of 180° through 500° F. Hence, the energy saving during the manufacturing process of the refractory itself is substantial.
  • the outside or bark surface of the outer layer 30 is preferably, but not necessarily, smoothed to a desired texture.
  • the cured refractory is most preferably cut at both ends along planes normal to the longitudinal axis of the refractory 2 so that a true cylinder is formed. Even though the refractory 2 can be achieved by the independent formation of two substantially identical main segments 13, the more efficient procedure is to manufacture a composite, laminated refractory 2 and then divide the refractory 2 by any suitable means into two substantially identical main segments 13.
  • the void 28 is sufficiently large to receive a longitudinally aligned pipe 20.
  • the void 28 and the body segment 6 occupy approximately 120° of cylindrical displacement.
  • a preferred thickness of the inner layer 32 is one-eighth inch through one-half inch.
  • the preferred thickness of the outer layer 30 is preferably one-eighth through one-half inch. It is realized that the longer the interlock portion of the refractory 2, that is those portions of the refractory generally defined by the interlocking recesses 16, 29 and protuberances 10 and 15 of each main segment 13, the more effective is the resulting interlocking action, stability of the refractory 2 around the blanket 26 and pipe 20 and the smaller are the seams which result when the two main segments 13 are interlocked.
  • the tapering of the protuberances and conforming recesses further reduces penetration through the seams by the slag and corrosive gases. Because of the remarkably improved weight characteristics of the new interlocking, laminated vacuum-formed ceramic fiber refractory, the weight per lineal foot has been reduced to two to three pounds as opposed to the thirty-five to forty pounds per lineal foot for the conventional prefired ceramic refractory tile. Hence, the weight and stress placed upon the water-cooled infrastructure is significantly reduced, and the loads and stresses on the protuberances 10 and 15 are reduced thereby reducing in turn the fractures and failures in those areas. Moreover, the reduced weight per lineal foot of the present invention substantially reduces the crushing effect of the refractory 2 on the blanket 26 when the blanket is maintained in compression inside the refractory 2.
  • the present invention is suitable for application as a process pipe insulation such as those insulations used in the petroleum or utility industry.
  • a thermal gradient is inverted such that the fluid inside the pipe is at a higher temperature than the surrounding atmosphere, it may be more efficient to invert the layers of the refractory wherein the inner layer is more suitable for high temperature environment than is the outer layer.
  • the resulting new and improved refractory greatly reduces heat loss through water-cooled pipes in a metallurgical furnace. For example, in a furnace operating between 2400° F. and 2500° F., the approximate following heat losses occur:

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Ceramic Engineering (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Rigid Pipes And Flexible Pipes (AREA)
  • Devices For Post-Treatments, Processing, Supply, Discharge, And Other Processes (AREA)
  • Manufacturing Of Tubular Articles Or Embedded Moulded Articles (AREA)
  • Thermal Insulation (AREA)
  • Furnace Housings, Linings, Walls, And Ceilings (AREA)
US05/950,633 1978-10-12 1978-10-12 Interlocking, laminated refractory for covering a pipe Expired - Lifetime US4228826A (en)

Priority Applications (11)

Application Number Priority Date Filing Date Title
US05/950,633 US4228826A (en) 1978-10-12 1978-10-12 Interlocking, laminated refractory for covering a pipe
CA330,374A CA1132450A (en) 1978-10-12 1979-06-22 Interlocking refractory for covering a pipe
MX17834379A MX152389A (es) 1978-10-12 1979-07-04 Mejoras en aislamiento refractario laminado de intersujecion para recubrir tuberia en un ambiente de alta temperatura
JP8638279A JPS5554793A (en) 1978-10-12 1979-07-06 Shaped piece of refractory ceramic fibers
ES483459A ES483459A1 (es) 1978-10-12 1979-08-17 Un dispositivo refractario de fibra ceramica para aislar un-tubo dentro de un medio ambiente de elevada temperatura.
AT79302116T ATE6495T1 (de) 1978-10-12 1979-10-04 Formteil aus feuerfesten keramischen fasern zum isolieren von rohren.
DE7979302116T DE2966759D1 (en) 1978-10-12 1979-10-04 Ceramic fibre refractory member for insulating a pipe
EP19790302116 EP0010385B1 (en) 1978-10-12 1979-10-04 Ceramic fibre refractory member for insulating a pipe
DD21611879A DD146487A5 (de) 1978-10-12 1979-10-09 Ineinandergreifendes,feuerfestes material zum umhuellen eines rohres
PL21893179A PL218931A1 (ru) 1978-10-12 1979-10-12
US06/173,211 US4304267A (en) 1978-10-12 1980-07-30 Interlocking refractory for covering a pipe

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US05/950,633 US4228826A (en) 1978-10-12 1978-10-12 Interlocking, laminated refractory for covering a pipe

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US06/173,211 Continuation-In-Part US4304267A (en) 1978-10-12 1980-07-30 Interlocking refractory for covering a pipe

Publications (1)

Publication Number Publication Date
US4228826A true US4228826A (en) 1980-10-21

Family

ID=25490695

Family Applications (1)

Application Number Title Priority Date Filing Date
US05/950,633 Expired - Lifetime US4228826A (en) 1978-10-12 1978-10-12 Interlocking, laminated refractory for covering a pipe

Country Status (2)

Country Link
US (1) US4228826A (ru)
JP (1) JPS5554793A (ru)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1981001451A1 (en) * 1979-11-15 1981-05-28 F Campbell Interlocking truncated triangular insulator
US4290589A (en) * 1979-03-17 1981-09-22 Didier-Werke Ag. Teeming pipe for use at the outlet of a melt container
US4362506A (en) * 1981-04-13 1982-12-07 Fulbright & Jaworski Single location insulator locking device
US5215126A (en) * 1990-02-08 1993-06-01 Foseco International Limited Insulation sheaths
GB2267559A (en) * 1992-05-23 1993-12-08 Detrick M H Co Composite heat insulating bodies and a method for producing same
US5410567A (en) * 1992-03-05 1995-04-25 Corning Incorporated Optical fiber draw furnace
US5470633A (en) * 1993-10-14 1995-11-28 Hexcel Corporation High thermal conductivity non-metallic honeycomb with optimum pitch fiber angle
US5693274A (en) * 1994-12-02 1997-12-02 Hyundai Motor Company Manufacturing method of prefrom for composite material of automobile
US6068027A (en) * 1996-03-06 2000-05-30 Seamark Systems Limited Pipeline insulation
US6102694A (en) * 1998-10-01 2000-08-15 M. H. Detrick Co. Pipe refractory insulation for furnaces
US6136117A (en) * 1996-12-12 2000-10-24 Ngk Insulators, Ltd. And Mitsubishi Heavy Industries, Ltd. Boiler tube protector and a method for attaching such protector to a boiler tube
US6431216B1 (en) * 2000-11-15 2002-08-13 Terry L. Briscoe Protective tube assembly
US20030075301A1 (en) * 1999-10-01 2003-04-24 Kimbrough Larry C. Ceramic fiber core for casting
US20050067038A1 (en) * 2003-09-30 2005-03-31 Tsuyoshi Kobayashi Heat insulating construction for piping and heat insulating tool kit
WO2006084827A1 (en) * 2005-02-14 2006-08-17 Luca Toncelli Method for manufacturing articles in the form of slabs
US20110027741A1 (en) * 2008-03-28 2011-02-03 Bloom Engineering Company, Inc. Vacuum-formed refractory member and method of making
WO2013017621A1 (fr) * 2011-08-01 2013-02-07 Commissariat à l'énergie atomique et aux énergies alternatives Tube multicouche ameliore en materiau composite a matrice ceramique, gaine de combustible nucleaire en resultant et procedes de fabrication associes
CN104334992A (zh) * 2012-05-23 2015-02-04 西格里碳素欧洲公司 热绝缘体及其制备方法
EP4141305A1 (en) * 2021-08-23 2023-03-01 Dhes B.V. Traced pipe arrangement

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5894689A (ja) * 1981-11-28 1983-06-04 株式会社ノリタケカンパニーリミテド セラミツク繊維入り強化陶管とその製造方法
JPS5830597A (ja) * 1982-05-29 1983-02-23 樽川　富次 耐火性管継手の製造方法
DE3313836C2 (de) * 1983-04-16 1985-08-29 W.C. Heraeus Gmbh, 6450 Hanau Verwendung von Aluminiumnitrid für Laserröhrenbauteile
JPS6089290A (ja) * 1983-10-19 1985-05-20 Ricoh Co Ltd パタ−ン認識方法
JPS60102587U (ja) * 1983-12-19 1985-07-12 北海道水道機材株式会社 水管橋の配水管被覆用継手
JP4491939B2 (ja) * 2000-09-01 2010-06-30 イビデン株式会社 燃料電池用改質器
US8771604B2 (en) * 2007-02-06 2014-07-08 Aerojet Rocketdyne Of De, Inc. Gasifier liner
JP2014005173A (ja) * 2012-06-25 2014-01-16 Mitsubishi Plastics Inc 無機繊維成形体及び断熱部材
CN109931460A (zh) * 2018-11-29 2019-06-25 苏州宏久航空防热材料科技有限公司 一种双壁可拆卸高温管道接头用保温罩
EP4001729B1 (en) * 2019-07-19 2024-04-17 MAFTEC Co., Ltd. Heat insulating protective member and installing the same

Citations (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1731991A (en) * 1926-04-26 1929-10-15 David D Tracy Waterproof conduit
US2693352A (en) * 1950-08-14 1954-11-02 Frederick S Bloom Furnace insulation system
US2884879A (en) * 1955-11-09 1959-05-05 Corriston John Wilson Insulated water-cooled furnace members
US3053715A (en) * 1958-03-17 1962-09-11 Johns Manville Fiber Glass Inc High temperature pipe insulation and method of making same
US3055651A (en) * 1960-09-02 1962-09-25 Babcock & Wilcox Co Interlocking ceramic tile elements
US3151633A (en) * 1961-03-29 1964-10-06 Owens Corning Fiberglass Corp Shaped thermal insulation for pipe
US3451661A (en) * 1967-08-14 1969-06-24 Morgan Refractories Ltd Protecting and insulating covering for furnace support members
US3486533A (en) * 1966-03-18 1969-12-30 Rust Furnace Co Pipe insulation jacket
US3488040A (en) * 1968-02-13 1970-01-06 Babcock & Wilcox Co Pipe sheathing tile
US3561494A (en) * 1968-03-04 1971-02-09 Robert J Hackett Castable silicate compositions, casting methods and articles produced thereby
US3572662A (en) * 1969-05-01 1971-03-30 Dresser Ind Skid rail system
US3706448A (en) * 1970-03-23 1972-12-19 British Iron Steel Research Skids or beams for furnaces
GB1318352A (en) * 1969-08-25 1973-05-31 Morgan Refractories Ltd Refractory sheathing for furnaces
GB1342891A (en) 1970-01-23 1974-01-03 Morgan Refractories Ltd Sheathing metal members in furnaces
US3914100A (en) * 1974-07-29 1975-10-21 Wheeling Pittsburgh Steel Corp Pipe protective covering
US3941160A (en) * 1974-02-08 1976-03-02 The Babcock & Wilcox Company Interlocking ceramic tile for covering an insulated water cooled pipe structure
US3986528A (en) * 1972-09-20 1976-10-19 E. I. Du Pont De Nemours And Company Reticulated tube of reinforced ceramic fibers
US4015636A (en) * 1975-12-04 1977-04-05 The Babcock & Wilcox Company Ceramic refractory covering members
US4063573A (en) * 1976-04-21 1977-12-20 The Carborundum Company Thermal insulation assembly
US4071311A (en) * 1976-02-12 1978-01-31 Morgan Refractories Limited Refractory insulation
US4095937A (en) * 1976-11-08 1978-06-20 Hitco Insulation for water cooled pipes in a reheating furnace

Patent Citations (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1731991A (en) * 1926-04-26 1929-10-15 David D Tracy Waterproof conduit
US2693352A (en) * 1950-08-14 1954-11-02 Frederick S Bloom Furnace insulation system
US2884879A (en) * 1955-11-09 1959-05-05 Corriston John Wilson Insulated water-cooled furnace members
US3053715A (en) * 1958-03-17 1962-09-11 Johns Manville Fiber Glass Inc High temperature pipe insulation and method of making same
US3055651A (en) * 1960-09-02 1962-09-25 Babcock & Wilcox Co Interlocking ceramic tile elements
US3151633A (en) * 1961-03-29 1964-10-06 Owens Corning Fiberglass Corp Shaped thermal insulation for pipe
US3486533A (en) * 1966-03-18 1969-12-30 Rust Furnace Co Pipe insulation jacket
US3451661A (en) * 1967-08-14 1969-06-24 Morgan Refractories Ltd Protecting and insulating covering for furnace support members
US3488040A (en) * 1968-02-13 1970-01-06 Babcock & Wilcox Co Pipe sheathing tile
US3561494A (en) * 1968-03-04 1971-02-09 Robert J Hackett Castable silicate compositions, casting methods and articles produced thereby
US3572662A (en) * 1969-05-01 1971-03-30 Dresser Ind Skid rail system
GB1318352A (en) * 1969-08-25 1973-05-31 Morgan Refractories Ltd Refractory sheathing for furnaces
GB1342891A (en) 1970-01-23 1974-01-03 Morgan Refractories Ltd Sheathing metal members in furnaces
US3706448A (en) * 1970-03-23 1972-12-19 British Iron Steel Research Skids or beams for furnaces
US3986528A (en) * 1972-09-20 1976-10-19 E. I. Du Pont De Nemours And Company Reticulated tube of reinforced ceramic fibers
US3941160A (en) * 1974-02-08 1976-03-02 The Babcock & Wilcox Company Interlocking ceramic tile for covering an insulated water cooled pipe structure
US3914100A (en) * 1974-07-29 1975-10-21 Wheeling Pittsburgh Steel Corp Pipe protective covering
US4015636A (en) * 1975-12-04 1977-04-05 The Babcock & Wilcox Company Ceramic refractory covering members
US4071311A (en) * 1976-02-12 1978-01-31 Morgan Refractories Limited Refractory insulation
US4063573A (en) * 1976-04-21 1977-12-20 The Carborundum Company Thermal insulation assembly
US4095937A (en) * 1976-11-08 1978-06-20 Hitco Insulation for water cooled pipes in a reheating furnace

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4290589A (en) * 1979-03-17 1981-09-22 Didier-Werke Ag. Teeming pipe for use at the outlet of a melt container
WO1981001451A1 (en) * 1979-11-15 1981-05-28 F Campbell Interlocking truncated triangular insulator
US4275771A (en) * 1979-11-15 1981-06-30 Campbell Frank Jun Interlocking truncated triangular insulator
US4362506A (en) * 1981-04-13 1982-12-07 Fulbright & Jaworski Single location insulator locking device
US5215126A (en) * 1990-02-08 1993-06-01 Foseco International Limited Insulation sheaths
EP0441526B1 (en) * 1990-02-08 1993-06-02 Foseco International Limited Insulation sheaths
US5410567A (en) * 1992-03-05 1995-04-25 Corning Incorporated Optical fiber draw furnace
GB2267559A (en) * 1992-05-23 1993-12-08 Detrick M H Co Composite heat insulating bodies and a method for producing same
US5470633A (en) * 1993-10-14 1995-11-28 Hexcel Corporation High thermal conductivity non-metallic honeycomb with optimum pitch fiber angle
US5693274A (en) * 1994-12-02 1997-12-02 Hyundai Motor Company Manufacturing method of prefrom for composite material of automobile
US6068027A (en) * 1996-03-06 2000-05-30 Seamark Systems Limited Pipeline insulation
US6136117A (en) * 1996-12-12 2000-10-24 Ngk Insulators, Ltd. And Mitsubishi Heavy Industries, Ltd. Boiler tube protector and a method for attaching such protector to a boiler tube
US6152087A (en) * 1996-12-12 2000-11-28 Ngk Insulators, Ltd. Boiler tube protector and a method for attaching such protector to a boiler tube
US6102694A (en) * 1998-10-01 2000-08-15 M. H. Detrick Co. Pipe refractory insulation for furnaces
US6868892B2 (en) 1999-10-01 2005-03-22 International Engine Intellectual Property Company, Llc Ceramic fiber core for casting
US20030075301A1 (en) * 1999-10-01 2003-04-24 Kimbrough Larry C. Ceramic fiber core for casting
US6431216B1 (en) * 2000-11-15 2002-08-13 Terry L. Briscoe Protective tube assembly
US20050067038A1 (en) * 2003-09-30 2005-03-31 Tsuyoshi Kobayashi Heat insulating construction for piping and heat insulating tool kit
WO2006084827A1 (en) * 2005-02-14 2006-08-17 Luca Toncelli Method for manufacturing articles in the form of slabs
US20080006956A1 (en) * 2005-02-14 2008-01-10 Luca Toncelli Method for manufacturing articles in the form of slabs with a siliceous binder and slabs thus obtained
US7695657B2 (en) * 2005-02-14 2010-04-13 Luca Toncelli Method for manufacturing articles in the form of slabs with a siliceous binder and slabs thus obtained
US20110027741A1 (en) * 2008-03-28 2011-02-03 Bloom Engineering Company, Inc. Vacuum-formed refractory member and method of making
WO2013017621A1 (fr) * 2011-08-01 2013-02-07 Commissariat à l'énergie atomique et aux énergies alternatives Tube multicouche ameliore en materiau composite a matrice ceramique, gaine de combustible nucleaire en resultant et procedes de fabrication associes
FR2978697A1 (fr) * 2011-08-01 2013-02-08 Commissariat Energie Atomique Tube multicouche ameliore en materiau composite a matrice ceramique, gaine de combustible nucleaire en resultant et procedes de fabrication associes
CN103732388A (zh) * 2011-08-01 2014-04-16 原子能和替代能源委员会 改进的由陶瓷基体复合材料制成的多层管、产生的核燃料包壳及相关生产方法
US20140153688A1 (en) * 2011-08-01 2014-06-05 Commissariat a I'energie atomique et aux energies Multilayer tube in ceramic matrix composite material, resulting nuclear fuel cladding and associated manufacturing processes
US9548139B2 (en) * 2011-08-01 2017-01-17 Commissariat A L'energie Atomique Et Aux Energies Alternatives Multilayer tube in ceramic matrix composite material, resulting nuclear fuel cladding and associated manufacturing processes
CN104334992A (zh) * 2012-05-23 2015-02-04 西格里碳素欧洲公司 热绝缘体及其制备方法
EP4141305A1 (en) * 2021-08-23 2023-03-01 Dhes B.V. Traced pipe arrangement

Also Published As

Publication number Publication date
JPS5554793A (en) 1980-04-22
JPS621160B2 (ru) 1987-01-12

Similar Documents

Publication Publication Date Title
US4228826A (en) Interlocking, laminated refractory for covering a pipe
US4304267A (en) Interlocking refractory for covering a pipe
US3781167A (en) No-weld refractory covering for water cooled pipes
EP0097482B1 (en) Refractory coverings for application to fluid conveying members
CA1215831A (en) Furnace wall construction for industrial use
US4275771A (en) Interlocking truncated triangular insulator
US4487631A (en) Shot-free millboard
KR0150792B1 (ko) 팽창성 설치패드
EP0010385B1 (en) Ceramic fibre refractory member for insulating a pipe
US4189301A (en) Reinforced insulating members
US6802709B1 (en) Rotary kiln with a hollow brick insulating lining
GB2103331A (en) Heat-insulating casing for elongate constructional parts
CA1145545A (en) Regenerative air preheater with improved insulation between combustion and checker shaft
US4402345A (en) Precast furnace pipe insulation
GB2039829A (en) An Insulating Block
US4802425A (en) High temperature fiber system with controlled shrinkage and stress resistance
JPH02277713A (ja) スキッドパイプ
DE60017120D1 (de) Feuerfeste beschichtung für gekühlte rohre
JP3679464B2 (ja) 混銑車の多層耐火ライニング構造
US20110027741A1 (en) Vacuum-formed refractory member and method of making
JP2651834B2 (ja) 高耐熱ロール
CA1195481A (en) Heat resistant process gas line
AU6642481A (en) Interlocking truncated triangular insulator
JPH0261493A (ja) 高耐熱ロール
SU881284A1 (ru) Дымова труба

Legal Events

Date Code Title Description
AS Assignment

Owner name: CAMERON IRON WORKS, INC., 13013 NORTHWEST FREEWAY,

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:CAMPBELL, FRANK, JR.;REEL/FRAME:004694/0282

Effective date: 19870325